After heavy rains, part of the Oroville Dam's spillway washed away, prompting the temporary evacuation of 188,000 residents living below the
earthen dam. The dam did not fail despite dramatic damage, sparing nearby cities of flooding.
"They said there were erosion conditions taking place on the
earthen dam and the concrete on the weir was in poor condition.''
An
earthen dam is made by compacting layers of soil.
The dramatic landscape is webbed with hiking routes such as six-mile Beaver Trail that winds through the hills, crosses an
earthen dam, then rims the shoreline of Pounds Hollow Lake.
An
earthen dam can fail within hours if water builds up behind the spillway gates, the gates are not lowered, and water proceeds to run over the top of the dam, so the corps builds extra ways of spilling water safely.
Recognized worldwide for modeling, designing, and engineering hydraulic structures for agriculture, the Stillwater facility today specializes in studying how water erodes spillways and forms gaps in
earthen dam walls or embankments.
The Mayak facility also has 200,000 Ci stored in a system of reservoirs that are in danger of overflowing an
earthen dam, he reported.
Unless things worsen, however, it should be smooth sailing for continued "full pool" operation of the
earthen dam, corps spokeswoman Heidi Helwig said Monday.
Army Corps of Engineers has determined that the
earthen dam's drainage system is in much better shape than previously thought.